Spotting for a valve drill

[limeyx]

That is exactly why it is not a good idea to "breathe down" a reg.

Better to switch first, then shut down.

There will need to be a major accident or two, before this correction is made in those training agencies that teach the breathing-down method, like everything in tech scuba.

You need to breathe it down so you can see if you have an isolator/manifold "failure" or a "post" failure. If you don't breathe it down, then gas in the hose can still bubble out, making you think you need to isolate when you do not.

 

[JeffG]

That is exactly why it is not a good idea to "breathe down" a reg.

You have to breathe down the reg so that it is no longer pressurized. Otherwise you would not know whither or not you fixed the problem. (a pressurized reg would still be making noises)

 

[JeffG]

There will need to be a major accident or two, before this correction is made in those training agencies that teach the breathing-down method, like everything in tech scuba.

Yea...like teaching left lean, right rich nonsense.

 

[TSandM]

My buddy of last night says he's had the problem of getting the secondary reg hose caught on the isolator knob and having that yank the secondary out of position. I wonder if that's what happened to me. He also thought my necklace was a little long, so I'm going to fix that.

I agree -- Having that backup regulator not where you expect to find it is NOT a good thing.

With regards to the breathing down thing . . . You could always switch, shut down and purge to depressurize, the way you do with a left post failure. I started to say that isn't what you'd do in a real emergency, but maybe it should be.

 

[nereas]

You need to breathe it down so you can see if you have an isolator/manifold "failure" or a "post" failure. If you don't breathe it down, then gas in the hose can still bubble out, making you think you need to isolate when you do not.

Thats funny, not isolating first. As in funny-dangerous. Long debate, of course, with no end in sight. The ghost of G.I. still haunting tech scuba.

 

[limeyx]

Yea...like teaching left lean, right rich nonsense.

Phew, thank god I mark all my second stages with different colors of masking tape -- that could never fail, right?

 

[nereas]

You need to breathe it down so you can see if you have an isolator/manifold "failure" or a "post" failure. If you don't breathe it down, then gas in the hose can still bubble out, making you think you need to isolate when you do not.

You can't purge it with the purge button and your thumb??

 

[nereas]

Phew, thank god I mark all my second stages with different colors of masking tape -- that could never fail, right?

Thank goodness for the ignor feature here.

 

[JeffG]

Thank goodness for the ignor feature here.

I don't use it. You are too funny to miss.

 

[limeyx]

Thats funny, not isolating first. As in funny-dangerous. Long debate, of course, with no end in sight. The ghost of G.I. still haunting tech scuba.

Whether you isolate first/last/can't even reach the isolator doesn't really matter. You have to purge the reg at some point to verify what the problem is (unless you actually like exiting on 1/2 gas for no reason).

I think the issue here is just verifying you have a known good gas to go to before shutting anything off, and if (for some reason) that gas source is bad when you go to it, hope you have a buddy that is paying attention.

Also, I cannot immediately see any issue with going to a new reg and then purging down the right post (in this case) -- maybe there is a reason though.

I am not willing to debate the isolate first/last/never issue here (or really anywhere) either